1. Field of the Invention
This invention relates generally to internal combustion engines and more particularly to a rotary internal combustion engine.
2. Description of the Prior Art
Many attempts have been made to devise an internal combustion engine of the type commonly referred to as a rotary engine due to its rotational operation as distinguished from the reciprocal operation of the more conventional piston-type engines.
In general, rotary engines include a rotor carried eccentrically within a fixed casing which defines the rotor chamber. The periphery of the rotor is divided, such as with radially extensible and retractable vanes, into plural segments each of which defines a combustion chamber. The plural combustion chambers are continuously changing in volume, i.e., expanding and contracting, as the rotor revolves eccentrically in the fixed rotor chamber casing, so that with proper porting, among other things, the rotary engine is capable of performing the necessary internal combustion engine functions of; fuel intake, compression, combustion and exhaust. The radially movable vanes provided at spaced increments about the periphery of the rotor must form a seal with the endless inner wall of the rotor chamber casing to sealingly divide the rotating combustion chambers from each other so that the different ones of the internal combustion engine functions can occur simultaneously in adjacent combustion chambers.
Combustion chamber sealing is a problem which has kept many of the prior art radial engines from becoming commercially acceptable. The high operating pressures and temperatures causes rapid wear of the seals which, when they become worn, allow the escape, or blow by, of the gasses, and form chatter marks on the endless inner sidewall of the rotor chamber casing. This, of course, results in a loss of engine performance and if not corrected quickly can damage, and in severe cases, ruin the rotor chamber casing.
The well known Wankel engine, although having achieved commercial acceptance, experienced considerable combustion chamber sealing problems which, even after extensive and costly research and development, remains a weak spot in the engine. The Wankel engine has a generally triangularly shaped rotor and a rotor chamber casing having its inner wall especially configured in a shape which is derived from a group of curves generally called trochoids. These special rotor and casing configurations place the three lobes, or tips, of the rotor in constant engagement with the endless inner wall of the rotor chamber casing without the need for radial movement as is the case in the prior art vane-type rotary engines. Although the very exotic and expensive tip seals developed for the Wankel engine are capable of withstanding the high operating pressures and temperatures of the engine, they are still subjected to high frictional wear which results in a relatively rapid wear rate.
Therefore, a need exists for a new and improved radial engine which overcomes, or at least substantially reduces, the problems of the prior art.